Carton forming machine



July 1969 L. c. ROESNER ET AL 3,456,563

CARTON FORMING MACHINE Filed June 22, 1967 10 Sheets-Sheet l Noe0e MOE/VINVENTURI IZY 47'70E/VE/5 July 22, 1969 1.. c. ROESNER ET AL 3,456,563

CARTON FORMING MACHINE 10 Sheets-Sheet 2 Filed June 22, 1967 Arman 5%July 22, 1969 c, ROESNER ET AL 3,456,563

CARTON FORMING MACHINE 10 Sheets-Sheet 5 Filed June 22, 1967 drraeA/EL rJuly 22, 19 69 3, ROESNER ET AL 3,456,563

CARTON FORMING MACHINE 1O Sheets-Sheet L Filed June 22, 1967 mm M M e CF. m e W m INVI-L'N'IURI [WM W ArroeMf/f L. c. ROESNER ET L 3,456,563

CARTON FORMING MACHINE July 22, 1969 10 Sheets-Sheet 5 Filed June 22,1967 N kh m w W I w NW. WWW w QA QM m5 0 0 @b. l. MW w Z. B Qmw v W mgJuly 22, 1969 L. c. ROESNER ET L 3, .5 3

CARTON FORMING MACHINE Fiied June 22. 1987 10 Sheets-Sheet v AflWf/Vt' 6wan/5e, LEN/0E0 5. MOE/V INVENTORI ww JM Jilly 22, 1969 c, RQESNER ET AL3,456,563

CARTON FORMING MACHINE 10 Sheets-Sheet 8 Filed June 22, 1967 5 WW WW zJuly 22, 1969 c. ROESNER ET AL 3,456,553

CARTON FORMING MACHINE Filed June 22, 1967 10 Sheets-Sheet 9 Arraewefl y1969 L. c. ROESNER ET AL 3,456,563

CARTON FORMING MACHINE l0 Sheets-Sheet 10 Filed June 22, 1967 2 M W H 5F. M W J m c m 7 mm M 4. MM w 45 1 LL 1 S 0 l fhl. 1 5 fil. F 5 I)United States Patent US. Cl. 9355 28 Claims ABSTRACT OF THE DISCLOSURE Amethod of and mechanism for forming cartons of a range of sizes frompreformed blanks and end panels, each blank having a rectangular bottompanel, hinged side panels along opposite sides of the bottom panel, andhinged adhesively coated inner and outer end flaps along opposite endsof the bottom panel and side panels, respectively, the forming operationinvolving initial mating engagement of a pair of end panels with thebottom panel of a preformed blank along opposite ends of the bottompanel, inward folding of the inner flaps into adhesive bonding contactwith the outer surfaces of the end panels, partial inward folding of theouter flaps toward the side panels, inward folding of the side panels tofinal folded positions of contact with the ends of the end panels tolocate the partially folded outer flaps in confronting relation to theouter surfaces of the end panels without wiping of the outer flapsacross these surfaces, and final inward folding of the outer flaps intoadhesive bonding contact with the end panels generally simultaneouslywith arrival of the side panels in their final folded positions. Acarton forming mechanism of the character described having a formingmandrel and blank folding members defining a mandrel receiving cavitywhich are adjustable to accommodate preformed blanks and end panels of arange of sizes.

REFERENCE TO COPENDING APPLICATION Reference is made herein to copendingapplication Ser. No. 428,462, filed Jan. 27, 1965, and entitled BottomSealing Machine, now Patent No. 3,342,116.

BACKGROUND OF THE INVENTION Summary of the invention This inventionrelates generally to carton forming machines. More particularly, theinvention relates to an ad- A great variety of carton forming machineshave been devised. One such machine is that disclosed in the abovementioned copending application. The machine disclosed in theapplication embodies a carton forming mechanism for mating separatepreformed end panels with a preformed blank and erecting the blank aboutand adhesively sealing the blank to the end panels to form a completedcarton. The blanks on which the machine operates have a centralrectangular bottom panel, hinged side panels along opposite sides of thebottom panel, and hinged adhesively coated inner and outer end flapsalong opposite ends of the bottom panel and side panels, respectively.The end panels are preferably laminated panels having a reinforcinglayer of Wood, or the like. The forming mechanism includes a rectangularforming mandrel Patented July 22, 1969 "ice and a rectangular formingcavity bounded along two opposite sides by fixed inner flap foldingmembers and along its remaining sides by movable, combined side paneland outer flap folding members.

Briefly, operation of the carton forming machine disclosed in thecopending application involves engagement of a pair of end panels withtwo opposite sides of the forming mandrel, extension of the mandrel tobring the end panels into initial mating engagement with the bottompanel of a preformed blank along the ends of the bottom panel and tothereafter force the blank and end panels into the forming cavity.During movement of the blank and end panels into and through the formingcavity, the inner flap folding members fold the inner flaps on the blankinwardly into adhesive bonding contact with the outer surfaces of theend panels, and the combined folding members fold the side panels of theblank inwardly against the ends of the end panels and simultaneouslyfold the outer flaps inwardly into adhesive bonding contact with theouter surfaces of the end panels. In addition to the carton formingmechanism, the machine is also equipped with blank infeed means forfeeding the preformed blanks in succession through a gluing station tothe forming mechanism, glue applicator means at the gluing station forcoating the flaps of each blank with glue, end panel infeed means forfeeding the preformed end panels in succession to opposite sides of theforming mandrel, and an outfeed conveyor for receiving the completedcartons from the forming cavity. These several machine components aredriven in unison in such a way that the machine operates automaticallyto produce completed cartons at a relatively high output rate.

The carton forming machine described above is very satisfactory from theoperational standpoint. However, this machine does possess certaindisadvantages. A major disadvantage of the machine, for example, residesin the fact that while the machine does embody certain adjustments toaccommodate preformed blanks and end panels of different sizes, theseadjustments are quite limited and difiicult to make.

Another disadvantage of the machine is that the carton forming operationis carried out by the forming mechanism of the machine in such a waythat the adhesively coated surfaces of the outer flaps contact and wipeacross the outer surfaces of the end panels during final folding ofthese flaps and the side panels against the end panels. This wipingcontact of the outer flaps with the end panels smears the glue on theflaps and results in an inferior adhesive bond between the flaps and endpanels. Moreover, such smearing of the glue tends to soil the cartons.

The carton forming machine of the copending application is subject tovarious other disadvantages. For example, in order to achieve aneffective adhesive bond between the end panels and the flaps of thepreformed blank of each carton, it is necessary to maintain the cartonunder endwise compression for a short period of time to allow the glueto set properly. To this end, the inner flap folding members of theforming mechanism comprise fixed plates which are spaced to frictionallygrip therebetween each completed carton. Accordingly, these plates exerta light inward compression on the completed cartons which maintains thecarton flaps in intimate sealing engagement with the carton end panelsduring setting of the glue. Each completed carton is pushed or ejectedfrom the forming cavity by the following carton during its formation inthe cavity. This method of ejecting the completed carton is not totallysatisfactory for the reason that, occasionally, a carton being formed inthe forming cavity will telescope within the preceding carton beingejected. This frequently causes jamming of the cartons in the formingcavity and other undesirable results. Moreover, a carton willoccasionally slide out of the forming cavity under its own weight beforethe end flaps of the carton are properly sealed.

Another deficiency of the carton forming machine disclosed in thecopending application is that the machine, When in operation, is quitenoisy. This noise is due, in large part, to an expanding and contractingaction which occurs in the forming mandrel of the forming mechanismduring each forming stroke of the mandrel. Thus, the two sides of theforming mandrel against which the end panels engage are pivotallymounted on the main body of the mandrel for swinging toward and awayfrom the inner flap folding plates of the forming mechanism. Operativelyconnected between these floating mandrel sides and the mandrel body aretoggle means which are operated by a lost motion means in such a waythat the toggle means are extended to locked position at the conclusionof each mandrel return stroke and retracted at the conclusion of eachmandrel forming stroke. Extension of the toggle means swings thefloating mandrel sides outwardly to effectively expand the mandrel inthe endwise direction of the carton being formed to provide the mandrelwith the proper dimension in this direction for forming the carton. Justprior to arrival of the forming mandrel at the limit of its formingstroke, the lost motion means operate to break the toggle means andthereby retract the floating mandrel sides inwardly. This actionreleases the pressure of the floating mandrel sides against the endpanels of the carton being formed and thereby permits retraction of themandrel from the forming cavity without pulling of the carton backthrough the forming cavity with the retracting mandrel. However, theaction produces considerable noise due to locking and unlocking of thetoggle means, arresting of the lost motion means, and oscillation of thefloating mandrel sides. Moreover, such action aggravates the gluesmearing problem discussed earlier.

SUMMARY OF THE INVENTION The present invention provides an improvedcarton forming mechanism for a carton forming machine of the kinddiscussed above. This improved forming mechanism has several uniquefeatures of construction and operation and several inherent advantageswhich will be explained as the description proceeds. Suflice it to sayat this point that the present forming mechanism avoids the majordisadvantages, just noted, of the forming mechanism embodied in theforming machine of the copending application. Thus, according to one ofits important aspects, the invention provides an improved formingmechanism which may be quickly and easily adjusted to accommodate arelatively wide range of preformed blank and end panel sizes, thus topermit forming completed cartons of a wide range of sizes. Theseadjustments permit variation in all three dimensions of the completedcartons. According to another of its important aspects, the inventionprovides an improved forming mechanism wherein the outer, adhesivelycoated flaps of each preformed blank are retained in a partially foldedposition during inward folding of the side panels of the blank to theirfinal folded positions of contact with the ends of the end panels. Inthese partially folded positions the outer flaps are disposed to clearthe outer surfaces of the end panels. The outer flaps are then foldedinwardly against the end panels approximately simultaneously with thearrival of the side panels in their final folded positions. Accordingly,the adhesively coated surfaces of the outer flaps do not slide acrossthe end panels as they do in the forming machine of the copendingapplication. Smearing of the glue on the outer flaps is thereby avoided,and a superior adhesive bond between the outer flaps and end panels isachieved.

In accordance with a further important aspect of the invention the meansfor effecting the delayed, outer flap folding action just referred to,are utilized to achieve another unique advantage. Thus, the outer flapfolding means of the present forming mechanism comprise floating outerflap folding members, or plates, which define the two opposite sides ofthe forming cavity adjacent the sides of the forming mandrel againstwhich the end panels engage and which are movable toward and away fromthe forming cavity. Adjacent and generally parallel to these floatingouter flap folding plates are fixed inner flap folding members orplates. During the major portion of each forming stroke of the formingmandrel, the floating plates are retracted a small distance outwardly,i.e., away from the forming cavity, relative to the fixed plates. As themandrel descends into the forming cavity, the fixed plates fold theinner flaps on the blank being formed inwardly against the outersurfaces of the mating end panels. The floating plates remain retracteduntil the side panels of the blank are substantially in their finalfolded positions of engagement with the ends of the end panels. Thispermits entrance of the partially folded outer flaps on the side panelsbetween the retracted floating plates and the end panels withoutcontacting the end panels and thereby smearing the glue on the flaps.The floating plates are driven inwardly to extended positionssubstantially flush with the fixed plates approximately simultaneouslywith arrival of the side panels in their final folded positions. Thefloating plates, when thus extended, fold the partially folded outerflaps inwardly against the end panels to complete the carton andcompress the latter in the endwise direction. This endwise compressionof the carton retains the flaps in effective sealing relation with theend panels during setting of the glue and, in addition, frictionallyretains the completed carton in the forming cavity. The floating platesare retracted during the following return stroke of the forming mandreland just prior to arrival of the mandrel at its fully retractedposition. Such retraction of the floating plates releases the completedcarton, which then drops from the forming cavity by gravity.Accordingly, the completed cartons are not ejected from the formingcavity by the following cartons, as in the forming machine of thecopending application, whereby the carton telescoping and jammingproblem, discussed above, is avoided.

Yet a further important aspect of the invention is concerned with animproved, relatively noiseless expanding and contracting action whichoccurs in the forming mandrel during its forming and return strokes.According to this aspect of the invention, the mandrel expanding andcontracting toggle means and lost motion connection of the earlierforming machine are replaced by a simple camming mechanism which causesexpansion of the mandrel during its forming stroke and retraction of themandrel during each return stroke. Unlike the mandrel expanding andcontracting means of the earlier forming machine, however, the presentmeans are relatively quiet in operation and thus do not contributeappreciably to the overall noise level generated by the machine.

At this point, attention is directed to the fact that the presentinvention 'is concerned only with an improved carton forming mechanismfor a carton forming machine of the general character described.Accordingly, only this forming mechanism will be disclosed in theapplication. It will be understood, however, that the present formingmechanism is intended for use in an overall carton forming machine ofthe general type disclosed in the aforementioned copending applicationand having blank and end panel infeed means and flap gluing means.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevational view ofthe presently preferred embodiment of the carton forming portion of themachine;

FIGURE 2 is an end elevational view taken on the line 22 of FIGURE 1;

FIGURE 3 is a horizontal cross-sectional view taken on the line 3-3 ofFIGURE 1;

FIGURE 4 is an enlarged fragmentary side elevational view taken on theline 4-4 of FIGURE 2;

FIGURE 5 is a fragmentary side elevational view taken on the line 5-5 ofFIGURE 2;

FIGURE 6 is a detail view of an internal drive mechanism;

FIGURE 7 is a cross-sectional view taken on the line 7-7 of FIGURE 6;

FIGURE 8 is a fragmentary horizontal cross-sectional view taken on theline 8-8 of FIGURE 4;

FIGURE 9 is a fragmentary horizontal cross-sectional view taken on theline 9-9 of FIGURE 4;

FIGURE 10 is a fragmentary end view taken on the line 10-10 of FIGURE 1;

FIGURE 11 is an enlarged fragmentary view of an internal portion of themachine, taken in the area 11-11 of FIGURE 10;

FIGURE 12 is a vertical cross-sectional view taken on the line 12-12 ofFIGURE 11;

FIGURE 13 is a vertical cross-sectional view taken on the line 13-13 ofFIGURE 11;

FIGURE 14 is a perspective view of the mandrel and associated portionsof the machine;

FIGURE 15 is an elevational cross-sectional view of the lower portion ofthe machine showing the ram in a lowered position during the forming ofa container;

FIGURE 16 is a plan view of one end of the container showing partialfolding of the end flaps;

FIGURE 17 is a plan view of the end of the container after the foldingof flaps has been completed;

FIGURE 18 is a perspective view of a preformed blank and one of the endpanels for the container; and

FIGURE 19 is a perspective view of the fully completed container.

DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is made first toFIGURE 18 which illustrates a typical preformed blank P and end panels Eof the type on which the present carton forming mechanism is designed tooperate. The blank P is commonly fabricated from cardboard or the likeand is stamped and creased or otherwise formed to the illustrated shape.The blank has a rectangular bottom panel B, hinged side panels S alongopposite sides of the bottom panel, hinged inner end flaps F alongopposite ends of the bottom panel, and hinged outer end flaps F alongopposite ends of the side panels. Each end panel B has a rectangularshape and, as noted earlier, may comprise a reinforced laminated panel.The length of each end panel is substantially equal to the width of thebottom panel B of the preformed blank P measured parallel to the endedges of the bottom panel.

According to the present invention, the completed carton C (FIGURE 19)is formed by initially coating the end flaps F and F of a preformedblank P with glue, bringing a pair of end panels E into matingengagement with the bottom panel B of the blank along the end edges ofthis panel, folding the adhesively coated inner flaps F inwardly intoadhesively bonding contact with the outer surfaces of the end panels,partially folding the adhesively coated outer end flaps F inwardlytoward the side panels S of the blank, folding the side panels inwardlyagainst the ends of the end panels to locate the partially folded outerend flaps in confronting relation with the outer surfaces of the endpanels without wiping of the outer flaps against the end panels, andfinally folding the outer flaps inwardly into adhesive bonding contactwith the end panels generally simultaneously with arrival of these sidepanels in their final folded positions of contact with the ends of theend panels. This forming method constitutes one important aspect of theinvention. The second important aspect of the invention is concernedwith a carton forming mechanism 10 for practicing or carrying out theforming method.

In general terms, the present carton forming mechanism 10 comprises aframe 12 mounting means 14 defining a generally rectangular formingcavity 16 having open ends. In this instance, the longitudinal axis ofthe cavity is vertical, whereby the cavity has open upper and lowerends. Supported on the frame 12 for movement along the longitudinal axisof the cavity is a forming mandrel 18. Mandrel 18 is movable between anextended position (FIGURE 15) wherein the mandrel projects into theforming cavity through its upper end, and a retracted position(FIGURE 1) wherein the mandrel is retracted from the cavity. Means 20are provided for driving the mandrel between these extended andretracted positions. Mandrel 18 has a generally uniform rectangularcross-section in planes normal to the longitudinal axis of the formingcavity 16. The mandrel is disposed with its sides parallel to the sidesof the cavity and generally complements the cavity. Mounted on twoopposite sides of the forming mandrel 18 are pawl means 22 which definethrust shoulders 24 facing the lower leading end of the mandrel. Thrustshoulders 24 are located rearwardly of and generally parallel to theleading end of the mandrel. The forming cavity defining means 14comprise inner end flap folding means 26 and outer end flap foldingmeans 28 along the two opposite sides of the forming cavity 16 adjacentthe mandrel t-hmst shoulders 24 and side panel folding means 30 alongthe two remaining sides of the cavity.

The forming mandrel 18, when retracted, is spaced from the upper end ofthe forming cavity 16 to permit placement of the preformed blank P in aninitial forming position across the upper end of the cavity, wherein thebottom panel B of the blank overlies the cavity, and placement of a pairof end panels E against the sides of the mandrel forwardly of its thrustshoulders 24. In this disclosure, it is assumed that the upper surfacesof the end flaps F and F of the preformed blank have been previouslycoated with glue G by passage of the blank through a gluing station 32immediately preceding the forming mechanism. Since this gluing stationforms no part of the present invention, it will not be described.

During each carton forming cycle of the mechanism 10, the formingmandrel 18 is driven forwardly or downwardly to its extended positionwithin the forming cavity 16 and is then returned rearwardly to itsretracted position. In the course of the forward forming stroke of themandrel, the mandrel thrust shoulders 24 engage the end panels E whichare currently in position against the sides of the mandrel and drivethese end panels forwardly to positions of initial mating engagementwith the preformed blank P currently in initial forming position,wherein the end panels engage the bottom panel B of the blank along theend edges of the bottom panel. Continued forward motion of the mandrelthen forces the blank and end panels into and through the formingcavity. As the blank and end panels enter and then pass through thecavity, the inner end flap folding means 26 fold the inner adhesivelycoated end flaps F on the blank inwardly into adhesive bonding contactwith the outer surfaces of the end panels. The outer end flap foldingmeans 28 initially partially fold the adhesively coated outer end flapsF of the blank inwardly toward the side panels S. The side panel foldingmeans 30 fold the side panels inwardly to final folded positions ofcontact with the ends of the end panels. During this folding of the sidepanels, the partially folded outer flaps F enter between the outer fiapfolding means 28 and the end panels E without contacting or wipingacross the end panels. Finally, and substantially simultaneously witharrival of the side panels S in their final folded positions of contactwith the end panels E, the outer flaps F, are folded inwardly intoadhesive bonding contact with the end panels by the outer fiap foldingmeans 28.

Referring now in more detail to the particular forming mechanism 10 ofthe invention which has been selected for illustration of the drawings,the frame 12 consists of rigid frame members which are welded orotherwise joined to form a rigid frame structure having an upper infeedlevel 34 at which the adhesively coated preformed blanks P arrive, insuccession, at their initial forming position within the formingmechanism and a lower outfeed 26 at which the completed cartons C emergefrom the forming mechanism. Rising above the infeed level 34 are rigidupright members 38 of the frame 12 which are arranged in pairs atopposite sides of the forming cavity 16. The upper ends of these mmebersare rigidly joined by horizontal cross members 40. Extending between thecross members 40 are a pair of mandrel supporting bars 42. The ends ofthese bars are secured to the cross members 40 by bolt and slotconnections 44 which permit adjustment of the spacing between the bars.

As indicated, bars 42 support the forming mandrel 18. To this end, thereare mounted on the inner confronting sides of these bars four rollerguide assemblies 46. Each bar carries a pair of the roller assemblies.Each guide roller assembly has a roller bracket 48 mounting a number ofguide rollers 50. Each roller bracket 48 is secured to its respectivesupporting bar 42 by bolt and slot connections 52 which permitadjustment of the spacing between two guide roller assemblies 46 on eachbar. It is evident at this point, therefore, that the guide rollerassemblies are adjustable in both horizontal directions of the formingcavity 16.

The forming mandrel 18 comprises two floating side frames 54,hereinafter referred to in places simply as floating sides. Each sideframe is a generally open rectangular frame structure including a pairof upright frame members 56 joined by upper, central, and lowerconnecting struts 58, 60, and 62, respectively. These connecting strutscomprise overlapping plates joined by bolt and slot connections 64 whichpermit adjustment of the space in between the two upright members 56 ofeach side frame. In addition to its floating side frame 54, the formingmandrel 18 includes a lower thrust plate 66. Welded t the two oppositeedges of this plate which extend normal to the floating side frames 54are lugs 68. Lugs 68 are located midway between the ends of these edgesand project above and below the plate. Seating on the upper and lowersurfaces of the thrust plate are cam follower supporting arms 72 whichparallel the lug mounting edges of the thrust plate 66 and have rigidlugs 74 which project laterally beyond the adjacent plate edges. The camfollower arms 72 are arranged in such a way that the two arms located atthe upper side of the thrust plate 66 extend toward opposite mandrelside frames 54, and the two arms located at the underside of the platealso extend toward opposite side frames. The cam follower arms aresecured to the thrust plate by bolts 76 which are threaded in the plateand extend through longitudinal slots in the arms. Thus, the followerarms are longitudinally adjustable toward and away from the mandrel sideframes 54. Operatively connected between the thrust plate lugs 68 andthe follower arm lugs 74 are adjusting screws 78 for longitudinallyadjusting the arms relative to the thrust plate.

Mounted on the outer ends of the arms 72 are cam follower rollers 80,hereinafter referred to simply as cam followers or followers. Thefollower 80 on each follower arm 70 engages in a cam slot 82 formed in acam plate 84 mounted on the lower end of the adjacent mandrel side frame54. Cam plates 84 are secured to the upper plates 62a of the lowermandrel side frame connecting struts 62. These plates are not directlyattached to the upright members 56 of the side frames. Thus, the spacein between the upright members may be adjusted, in the manner explainedearlier, while the space in between the cam plates on each mandrel sideframe remains fixed. The two cam plates on each mandrel side frame 54straddle the adjacent follower arms 72. Secured to and extendinginwardly from the inner surfaces of each cam plate 84, over the adjacentfollower arm 72, is a lug 86 which seats the upper end of a compressionspring 88. The lower end of this spring seats against the underlyingfollower arm.

It is now evident that the mandrel thrust plate 66 is secured to thelower ends of the floating mandrel side frames 54 through theinterengaging cam followers 80 and cam slots 82. The springs 88 urge theside frames upwardly to positions wherein the followers are located atthe lower ends of the cam slots. The cam slots 82 are inclined relativeto the longitudinal axis of the mandrel 18 in such a way that upwardmovement of the followers 80 in the cam slots, against the action of thefollower springs 88, draws the lower ends of the mandrel side frames 54inwardly toward one another, thereby effectively contracting the lowerleading end of the mandrel. Downward movement of the followers in thecam slots moves the lower ends of the mandrel side frames outwardly awayfrom one another, thereby effectively expanding the leading end of themandrel.

As noted earlier, the forming mandrel 18 is supported by the guideroller assemblies 46. In this regard, it will be observed that theupright members 56 of the mandrel side frames 54 extend through theroller assemblies in such a way that the rollers of these assembliessupport the members in all lateral directions. Thus, the forming mandrel18 is supported by the roller assemblies for vertical movement betweenits extended and retracted positions, referred to earlier. The widthdimension of the mandrel parallel to the planes of the floating mandrelside frames 54 is adjustable by adjusting the side frame connectingstruts 58, 60, 62. The width dimension of the mandrel normal to the sideframes is adjustable by longitudinally adjusting the cam followersupport arms 72 relative to the mandrel thrust plate 66. This latteradjustment is accomplished by rotating the follower arm adjusting screws78. The reasons for the mandrel adjustments will be explained presently.Suffice it to say at this point that the mandrel guide roller assemblies46 and/or their supporting bars 42 are adjusted when any adjustment ismade in the mandrel in such a way that the longitudinal axis of themandrel remains in coincidence with the longitudinal axis of the formingcavity 16, and the mandrel side frame 54 remain parallel to one anotherwhen the cam followers are located at the lower ends of their cam slots82.

The illustrated mandrel driving means 20 is a pneumatic or hydraulic ramincluding a cylinder 90 containing a plunger 92 which extends from thelower end of the cylinder. The ram cylinder 90 is rigidly mounted on theframe 12 of the forming mechanism in such a way that the cylinder axiscoincides with the longitudinal axis of the forming cavity 16. To thisend, the lower end of the cylinder is rigidly attached to a plate 04,the ends of which are welded or otherwise firmly attached to hori zontalmembers 96 on the frame 12. These horizontal members are secured to theupright frame members 38. The lower thrust plate 66 0f vthe formingmandrel 18 is located below and on the axis of the ram cylinder 90. Thelower end of the ram plunger 92 is threaded in a central opening in thethrust plate. Threaded 0n the plunger at opposite sides of the plate arejam nuts 98 which lock the plate in position. It is now evident,therefore, that the forming mandrel 18 may be driven between itsextended and retracted positions by the ram 20.

Flow of pressurized working fluid to and from the ram 20 is controlledby solenoid valve means (not shown) operated by switches 100 and 102mounted on one of the mandrel guide roller supporting bars 42. Theseswitches have rocker actuators 104 and 106, respectively. Adjustablysecured to an upright bar 108 attached to the mandrel side frame 54adjacent the switches are switch operators or targets 110 and 112. Thesetargets are independently adjustable along their supporting bar. Thelower target 110 operates the switch 100. The upper target 112 operatesthe switch 102. As will appear presently, the

switches are operated by their respective targets in such a way that theforming mandrel 18 is driven up and down alternatively through itsforming and return strokes.

As noted earlier, the forming mandrel 18 carries pawl means 22 fengaging a pair of end panels E placed against the sides of the mandrel,forwardly of the pawl thrust shoulders 24. In the illustrated formingmechanism, these pawl means comprise a pair of pawl assemblies 114mounted on each mandrel side frame 54. The two pawl assemblies on eachside frame comprise mounting plates 116 having flanges 118 at their endswhich seat against the inner sides of the respective upright side framemembers 56. Each mounting plate flange 118 is secured to the adjacentside frame member 56 by bolts 120 which extend through slots 122 in theflange. Accordingly, each pawl assembly is adjustable lengthwise of itsrespective side frame member. In addition, the upright members 56 of themandrel side frames 54 are provided with a num- *ber of threaded boltholes spaced therealong, as shown, to permit additional adjustment ofthe pawl assemblies 114 relative to the mandrel side frames.

Pivotally supported on each pawl mounting plate 116 is an end panel feedpawl 124. The illustrated pawl is fashioned from relatively heavy gaugesheet stock which is bent to the illustrated shape, whereby the pawl hasan upper leg 124a, a lower leg 124b, and a central connecting portion124c. The pawl is secured to the underside of its mounting plate 116 bya bolt 126 which passes through a slightly enlarged hole in the pawlcentral portion and is threaded in the lower edge of the plate.Surrounding this bolt is a spring 130 which yieldably urges the pawlcentral portion 124a into seating contact with the lower plate edge. Itwill be observed that the pawl can rock about the lower inner edge ofits mounting plate 116 as a fulcrum. Normally, the feed pawl is retainedin an extended position by the pawl spring 130, wherein the lower pawlleg 124b projects outwardly beyond the outer side of the adjacentfloating mandrel side frame 54. For convenience in the ensuingdescription, these mandrel side frames are hereinafter referred to, inplaces, simply as the floating sides of the mandrel.

Extending from the inner side of each pawl mounting plate 116 is a screw132 which passes through a slightly enlarged hole in the upper leg 124aof the respective end panel feed pawl 124. A nut 134 threaded on thisscrew is adjustable along the screw into engagement with the pawl leg toadjust the projection of the lower pawl leg 124b beyond the adjacentouter floating sides of the mandrel in the normal extended position ofthe pawl. Welded or otherwise secured to the lower end of the lower pawlleg 124b is an inwardly inclined cam plate 136 and an interveningspacer. This spacer defines with the lower edge of the pawl proper thepawl thrust shoulder 24. The width of this shoulder is just slightlyless than the thickness of the individual carton end panels E.

Mounted on the frame above the infeed level 34 are two end panel infeedmeans 138 for feeding the carton end panels E in succession to positionsof seating engagement with the opposite floating sides 54 of the formingmandrel 18, just forwardly of the mandrel thrust shoulders 24. These endpanel infeed means may be like those disclosed in the aforementionedcopending application and form no part of this invention. Accordingly,such infeed means will not be described in detail. Suflice it to saidthat the infeed means comprise end panel magazines 139 having lower endpanel supporting walls 140. These walls are located at a common level ashort distance above the infeed level 34. The inner edges of themagazine walls 140 are spaced outwardly from the planes of the outerside of the adjacent floating mandrel sides, or side frames 54, adistance substantially equal to or just slightly greater than thethickness of the preformed end panels E. Projecting inwardly from theseedges, a distance less than the end panel thickness, are yieldabledetents 142. The end panel magazines 139 are adjustable toward and awayfrom the forming mandrel 18 and in width, for reasons to be explainedpresently, Mounted for vertical adjustment on the mandrel guide rollersupporting bars 42 are end panel hold downs 144 which are secured inadjusted positions by bolts 146.

When the forming mandrel 18 is fully retracted, the lower leading end ofthe mandrel is located a distance above the infeed level 34 and at thelevel of the end panel infeed magazines 139. The end panels E containedin these magazines are constantly urged inwardly to posi tions whereinthe innermost panels seat against the floating sides of the mandrel. Themandrel feed pawl assemblies 114 are vertically adjusted relative to theforming mandrel 18 so that in this retracted position of the mandrel,the pawl shoulders 24 are located just above the upper edges of theinnermost end panels in the magazine. The pawl adjusting nuts 134 areset so that the pawls project beyond the outer surfaces of the floatingmandrel sides 54 a distance somewhat greater than the end panelthickness.

At this point, it is evident that when the forming mandrel 18 isretracted, the innermost end panels E contained within the end panelinfeed magazines 139 seat against the floating sides 54 of the mandreljust forwardly of, i.e., just below, the mandrel thrust shoulders 24.The innermost panels are vertically supported at this time by themagazine detents 142. Assume now that the forming mandrel 18 is extendeddownwardly by its forming ram 20 and into the forming cavity 16. As theforming mandrel descends, the mandrel pawls 124 are cammed inwardly byvirtue of the camming engagement of the descending pawl cam plates 136with the innermost end panels E. This camming action continues until thepawl thrust shoulders 24 engage the upper edge surfaces of the innermostend panels E. These end panels are then driven downwardly with theforming mandrel 18, through or across the infeed level 34, and finallyinto the forming cavity 16. As noted earlier and hereinafter explained,the end panels are thereby brought into initial mating engagement withthe preformed blank P currently in initial forming position at theinfeed level 34, after which the blank and end panels are forced intothe forming cavity to erect the blank about the end panels.

It will be recalled that the forming cavity 16 is defined by means 14including inner and outer end flap folding means 26, 28 and side panelfolding means 30. The outer end flap folding means 28 comprise two pairof floating, coplanar outer flap folding members 148 located at the twoopposite sides of the forming cavity 16 adjacent the floating sides 54of the forming mandrel 18. The two flap folding members in each of thesemember pairs are spaced to define therebetween a clearance opening 150extending endwise, i.e., vertically of the forming cavity. In thisinstance, the two floating, outer end flap floating members 148 in eachside of the forming cavity 16 comprise the two upright legs of agenerally U-shaped folding plate 152. The central cut out in this platebetween the legs provides the clearance opening 150. The folding membersor legs 148 of each folding plate 152 are integrally joined at thebottom of the plate. The inner end flap folding means 26 comprise a pairof fixed folding members or plates 154. These fixed plates are locatedat opposite sides of the forming cavity 16, within the clearance opening150, respectively, in the floating, outer end flap folding plates 152.

The floating outer end flap folding plates 152 and fixed inner flapfolding plates 154 are carried by adjustable hanger assemblies 156. Eachhanger assembly 156 has an upper supporting beam 158 which extendsparallel to the floating sides 54 of the forming mandrel 18 and issupported at its ends on horizontal cross members 160 of the frame 20.These cross members and the upper surfaces of the hanger beams 158 arelocated a small distance below the infeed level 34. Each hangersupporting beam 158 is a metal angle having a vertical flange 162 towhich is attached a depending hanger frame 164. The hanger frameincludes a pair of depending frame members or straps 166 which arejoined at their upper ends by a cross plate 168, at their centers by across bar 170, and at their lower ends by a mounting plate 172. Theupper cross plate 168 is bolted to the vertical flange of the respectivehanger support beam 158.

The center cross bar 170 of each hanger frame extends a distance beyondthe opposite vertical edges of the adjacent floating end flap foldingplate 152.

The fixed inner end flap folding plates 154 are secured to the innersides of the supporting beam 158 and hanger frame 164 of the hangerassemblies 156, respectively. The inner surfaces of these plates aresmooth and flat and are located in mutually parallel planes parallel tothe floating sides 54 of the forming mandrel 18 when these floatingmandrel sides are extended. As will appear presently, the space inbetween the parallel inner surfaces of the fixed end flap folding plates154 is slightly greater than the fully expanded width of the formingmandrel 18, measured between its floating sides 54.

The floating outer end flap folding plates 152 are supported on thehanger assemblies 156 for floating movement toward and away from theintervening forming cavity 16. To this end, each hanger assembly isequipped with a pair of suspension rods 174. The upper ends of theserods are pivotally attached, by hinge brackets 17-6, to the uppersupporting beam 158 of the respective assembly. The lower ends of therods are pivotally attached, by hinged brackets 178, to the lower endsof the adjacent floating plate 152. The suspension rods 174 carry theentire weight of these floating plates and permit the latter to move orfloat toward and away from the forming cavity 16. Threaded in the outerside of each floating plate 152 are a pair of upper studs 180 whichextend through slightly enlarged holes in the respective hanger beams158 and a pair of lower studs 182 which extend through slightly enlargedholes in the lower hanger frame mounting plate 172. Nuts 184 arethreaded on the outer ends of these studs and are retained in positionon the studs by wire retainers 186. Surrounding the studs 180 aresprings 188 which urge the floating outer end flap folding plates 152outwardly, i.e., away from the forming cavity 16. The folding plates aremovable inwardly towards the forming cavity against the action of thesprings 188.

Inward movement or extension of the lower ends of the folding plates 152is limited by engagement of limit stops 190 on the plates with the lowermounting plates 172 on the hanger frames 164. Inward movement orextension of the upper ends of the folding plates is limited by stopsleeves 192 on the upper folding plates studs 180.

Also mounted on each hanger assembly 156, outboard of the floating,outer end flap folding plate 152 are a pair of fixed and generallytriangular, outer end flap folding I plates 194. The upper ends of theselatter fixed plates are secured to the inner sides of the respectivehanger support beams 158. The lower ends of the plates 194 are securedto the adjacent outer ends of the respective hanger frame cross bar 170.As will appear presently, the inner surfaces of the fixed outer end flapfolding plates 194 and the inner surface of the floating outer end flapfolding plate 152 on each hanger assembly 156 are flush, i.e., coplanar,when the latter plate is retracted to its outer limiting position awayfrom the forming cavity 16 by the floating plate springs 188. When eachfloating plate 152 is fully extended inwardly toward a cavity, the innersurface of the plate is flush with the inner surface of the adjacentfixed inner end flap folding plate 26.

Mounted on each hanger assembly 156 are three fluid pressure actuators196, 198. The two upper actuators 196 are mounted on the correspondinghanger support beam 158 and have plungers 200. These plungers are driveninwardly against the upper ends of the adjacent floating, outer end flapfolding plate 152 when the actuators are pressurized, thus to extend theupper end of the floating plate inwardly toward the forming cavity 16.The lower actuator 198 is mounted on the corresponding lower hangerframe mounting plate 172 and has a plunger 202 which is driven inwardlyagainst the lower end of the floating plate 152 to extend this lower endof the plate inwardly towards the forming cavity.

As will appear presently, the several fluid pressure actuators 196, 198for both floating outer end flap folding plates 152 are simultaneouslypressurized and vented by solenoid valve means 203. These valve meansare controlled by a switch to be described. Simultaneous pressurizing ofthe actuators obviously drives the floating plates 152 inwardly towardthe forming cavity 16. Simultaneous venting of the actuators permitsspring retraction of the floating plates.

It is significant to note at this point that the upper edges of theseveral end flap folding plates 152, 154, 194 project above the hangersupport beams 158 and are located in a common plane which coincides withthe blank infeed level 34. This plane passes between sets of poweredblank infeed rollers 206 in the gluing station 32 immediately precedingthe forming mechanism 10. This gluing station may be like that disclosedin the aforementioned copending application and forms no part of thepresent invention. Accordingly, the gluing station will not be describedin detail. Suffice it to say that the feed rollers 206 feed preformedblanks P with adhesively coated end flaps F and F from the gluingstation 32 through an initial forming position within the formingmechanism 10. In this initial forming position, the bottom panel B ofthe blank overlies the forming cavity 16, the inner end flaps F, of theblank rest on the upper edges of the fixed inner end flap folding plates154, and the outer end flaps P of the blank rest on the upper edges ofthe floating and fixed outer end flap folding plates 152, 194.

From the preceding description, it will be understood that the hangerassemblies 156, along with the several components mounted on theseassemblies, are adjustable toward and away from the intervening formingcavity 16 to vary the space in between the end flap folding plates 152,154, 194- of these assemblies. Adjustment of the hanger assemblies maybe accomplished in various ways. In the drawings, the ends of eachhanger support beam 158 mount nuts 208 which are welded to the beam.Threaded in these nuts are adjusting screws 210 which extend rotatablythrough and are axially restrained by bearing plates 212 fixed toopposite sides of the frame 12. Additional adjusting screws 213 arethreaded in the lower ends of the hanger frames 164 and extend rotatablythrough and are axially restrained by members of the frame 20 foradjusting and supporting the lower ends of the hanger assemblies 156.Rotation of the adjusting screws 210, 213 obviously adjusts the hangerassemblies 156 toward and away from the intervening forming cavity 16.The ends of the hanger support beams 158 are secured to their adjacentframe supporting members by bolt and slot connections 214 which permitthe above described hanger assembly adjustment.

Returning now to the forming cavity defining means 14, the latter willbe recalled to comprise, in addition to the elements already discussed,side panel folding means 39. These side panel folding means compriserotary panel folding members 216. Each panel folding member 216 includesa rocker shaft 218 supported at its ends in bearings 220 and mounting apair of folding arms 222. These arms are keyed to the shaft foradjustment along the shaft while the arms are retained in alignmentaxially of the shaft. Means are provided for securing the arms inadjusted position relative to the rocker shaft. The two side flapfolding members 216 are located between and adjacent the vertical edgesof the floating outer end flap folding plates 152 with the axes of therocker shafts 218 extending normal to the plates. The rocker shafts arelocated at the same level, which is just below the hanger frame crossbars 170 and between the upper and lower edges of the floating plates152. The shaft bearings 220 are secured to horizontal supporting members224 on the frame 20 by 'bolt and slot connections 226. These bolt andslot connections permit lateral adjustment of the floating members 216toward and away from the intervening forming cavity 16.

The side panel folding arms 222 have a generally L- shape. Thus, eacharm includes an inner or lower end 222a which extends radially of itsrespective rocker shafts 218 and an outer or upper end 22% which extendsat an acute angle to the lower end and curves outwardly at its tip. The.folding arms 222 are rotatable between inner extended positions, whereinthe upper arm ends 2221) are vertical and parallel to the adjacent sidesof the forming mandrel 18, and outer retracted positions wherein theupper arm extends outwardly at acute angles relative to the vertical andin diverging relation to one another. The upper tip ends of the arms arelocated below the infeed level 34" so as to not interfere with infeedmovement of the preformed blanks P to initial forming position.

The rocket shafts 218 are driven in oscillation, to rotate the foldingarms 222 between extended and retracted positions, by fluid pressureactuators 228. Each actuator 228 includes a lower cylinder 230 and aplunger 232 which extends from the upper end of the cylinder. The lowerends of the actuator cylinders 230 are pivotally attached to the ends ofa beam 234 which is secured to the frame 12 for vertical adjustmentrelative to the frame. The upper endsof the actuator plungers 232 arepivotally attached to arms 236 rigid on corresponding ends of the rockershafts 218. Fluid pressure to the cylinders 230 is controlled by a valve238 in such a way that the actuator plungers 232 extend and retract inunison and thereby oscillate the folding arms 222 between extended andretracted positions in unison.

In order to assure precisely synchronized extension and retraction ofthe side panel folding arms 222, which is desirable for reasons to beexplained presently, corresponding ends of the rocker shafts 218 mountpinions or gears 240. These gears mesh with a gear rack 242. Rack 242 isretained in meshing engagement with the pinions 240 by spring 244. Rack242 engages the gears in the manner illustrated, whereby rotation ofeither rocker shaft tends to drive the other rocker shaft through thesame angle in the opposite direction. The rack is disengagable from therocker shaft gears 240 by withdrawing the rack away from the gearsagainst spring pressure, thus to permit relative rotation of the rockershafts 218 to locate their folding arms 222 in corresponding positions.If desired, the two ends of the rack 242 may be made longitudinallyadjustable relative to one another, in the manner illustrated, to permitfine adjustment of the relative angular positions of the folding arms.

Mounted adjacent one rocker shaft 218, for adjustment with the shaftbearings 220, is a switch 246 operated by an arm 248 on the shaft. Thisswitch operates the valve 203 which controls fluid flow to and from thefluid pressure actuators 196, 198 for the floating outer end flapfolding plates 152. As will appear presently, the switch 246 is operatedto pressurize the actuators in response to rotation of the side panelfolding arms 222 to their extended positions and approximatelysimultaneously with arrival of the arms in their extended positions. Theactuators are vented during outward retraction of the folding arms topermit spring retraction of the floating plates 152.

The operation of the illustrated forming mechanism 10 will now bedescribed. Assuming that the forming mandrel 18 is initially in itsfully retracted position, a preformed blank P with adhesively coated endflaps F and F is delivered to initial forming position over the upperend of the forming cavity 16. In this initial forming position, thebottom panel B overlies and is centered relative to the forming cavityand the end flaps F, and P of the blank rest in the upper edges of theend flap folding plates 152, 154, 194. More specifically, the innerflaps F rest on t e upper edges of the fixed folding plates 154 and theouter flaps F rest on the upper edges of the floating folding plates 152and the fixed floating plates 194. In this connection, it is significantto note that the width of the fixed inner end flap folding plates 154 ismade slightly less than the length of the inner flaps F on the smallestblank P on which the forming mechanism is to operate.

With the forming mandrel 18 in its initially retracted position, theinnermost end panels E in the end panel storage magazines 39 seatagainst the floating sides 54 of the mandrel, forwardly of the currentlyextended thrust shoulders 24. The mandrel cam followers are currentlyretained in the lower ends of their cam slots 82 by the follower springs88. Accordingly, the leading end of the forming mandrel is expanded toits full width, and the floating sides 54 of the mandrel are verticaland parallel to the inner surfaces of the end flap folding plates 152,154, and 194.

In the initial condition of the forming mechanism 10 underconsideration, the floating outer end flap folding plates 152 areretained in their fully retracted positions by the plate springs 188. Inthese retracted positions, the inner surfaces of the plates 152 areflush with the lnner surfaces of the fixed outer end flap folding plates194 and are displaced outwardly, away from the forming cavity 16,relative to the inner surfaces of the fixed inner end flap foldingplates 154. The side panel folding members 216 are fully retracted.

Assume now that the driving ram for the forming mandrel 18 ispressurized in a direction to drive the mandrel downwardly through itsextended position within the forming cavity 16. During the initialtravel of the mandrel, the mandrel thrust shoulders 24 engage the upperedges of the innermost carton end flaps E, wh ch are currentlyvertically supported by the inner magazine detents 142, and drive theinner end flaps downwardly into initial mating engagement with theunderlying adhesively coated blank P currently in initial formn gposition over the forming cavity 16. As noted earlier, in this initialforming position, the adhesively coated end flaps F, and F, of the blankrest on the upper edges of the end flap folding plates 152, 154, and194. The space in between the fixed, inner end flap folding plates 1541sadjusted, in the manner referred to earlier and hereinafter discussed,so that the upper edges of these plates engage the inner end flaps F, ofthe preformed blank close to the end edges of the bottom panel B of theblank. The width dimension of the forming mandrel 18, normal to itsfloating sides 54, is adjusted so that in their positions of initialmating engagement with the blank, the end panels E currently descendingwith the mandrel engage the bottom wall of the blank along its endedges.

Accordingly, continued downward movement of the forming mandrel 18 andits engaging end panels B, after initial mating engagement of these endpanels with the bottom wall B of the preformed blank P currently ininitial forming position, forces the blank and end panels into theforming cavity 16. As the blank enters the cavity, the inner end flapsF, on the blank are folded upwardly and inwardly by the fixed inner endpanel folding plates 154 and into adhesive bonding contact with theouter sur faces of the descending end panels E. Simultaneously, theouter end flaps F are partially folded inwardly toward the side panels Sof the blank by the currently retracted floating outer end flap foldingplates 152 and the fixed outer end flap folding plates 194. Because ofthe stiffness of the blank, this partial inward folding of the outerflaps F also tends to fold the side flaps S upwardly. That the outerflaps F are only partially folded, and the reason for this partialfolding, will appear presently.

Shortly after the leading end of the descending forming mandrel 18enters the forming cavity 16, and after the end flaps F F and sidepanels S of the blank have been folded in the manner just explained, thevalve 238 is operated to pressurize the side panel folding actuators 228in directions to rotate the side panel folding arms 222 inwardly totheir extended positions. During this inward extension of the foldingarms, they engage the currently partially folded side panels S of thedescending blank P and fold these side panels upwardly and inwardly tofinal folded positions of contact with the ends of the descending endpanels E. During this inward folding of the side panels, the outer edgesof the outer end flaps F on the side panels slide along the innersurfaces of the outer end flap folding plates 152, 194 to finalpositions wherein the inner adhesively coated surfaces ofthese flaps aredisposed in confronting relation to the outer surfaces of the descendingend panels E. In this regard, it will be understood that the width,referred to earlier, of the fixed inner end flap folding plates 154 issuch that the side panels S may be folded to their final foldedpositions, which is referred to, without interference between the outerend flaps F on these panels and the fixed plates.

At this point it is significant to recall that the floating outer endflap folding plates 152 are currently in their outer retractedpositions. It is evident, therefore, that the outer end flaps F on thepreformed blank P currently being erected about the descending endpanels E are only partially folded; that is to say, these outer endflaps incline outwardly at acute angles relative to the vertical planescontaining the outer side faces of the current end panels E.Accordingly, during inward folding of the side panels S to their finalfolded positions of contact with the ends of the end panels E, in themanner just explained, the partially folded outer end flaps F on theside panels enter between the currently retracted folding plates 152 andthe end panels without actually contacting or wiping across the outersurfaces of these panels. As a result, smearing or wiping of the glue onthe outer end flaps is avoided and a superior bond is produced in thecompleted carton. Approximately simultaneously with arrival of thecurrently inwardly rotating side panel folding arms 222 in theirextended positions, the switch 246 is actuated by" its respective rockershaft actuator arm 248. This operation of the switch pressurizes thefloating plate actuators 196, 198, thereby driving the floating outerend flap folding plates 152 inwardly. This action folds the partiallyfolded outer flaps F on the descending preformed blank P inwardly intoadhesive bonding contact with the descending end panels E, thus tocomplete the carton.

At this point, the driving ram 20 for the forming mandrel 18 is reversedto retract the mandrel upwardly.

During this upward return stroke of the mandrel, the floating sideframes 54 of the mandrel tend to remain stationary because of inertia,friction, and other forces. Accordingly, the mandrel cam followerrollers 80 ride upwardly in their cam slots 82 to cam the side framesinwardly. This releases the just completed carton C and prevents thelatter from being dragged upwardly through the forming cavity 16 withthe retracting mandrel. However, the completed carton does notimmediately drop through the forming cavity at this time because of thepressure of the extended folding plates 152 against the ends of thecarton which is now located below the fixed folding plates 26 andbetween the lower ends of the plates 152. Just before the formingmandrel reaches the upper limit of its stroke, the floating plates 152are again retracted to release the completed carton. This carton thendrops downwardly by gravity through the forming cavity 16 and onto anunderlying outfeed conveyor 250. The following adhesively coatedpreformed blank P is then delivered to initial forming position and thecarton forming cycle, just described, is repeated. Mounted on the frame20, just beyond the forming mechanism 10, is a switch 252 against whicheach blank P engages upon arrival at its initial forming position. Thisswitch, and the mandrel switches 100, 102 referred to earlier, serve tocause the forming mandrel 18 to proceed through its forming and returnstrokes in synchronism with movement of the preformed blanks to theforming mechanism. Thus, actuation of switch 252 by each preformed blankP arriving in initial forming position initiates the following formingcycle of the mechanism. The resulting forming stroke of the mandrel isterminated and the return stroke is initiated in response to operationof the mandrel switch ,102 by the mandrel target 112. The mandrel isconditioned for its following forming stroke, in response to the nextactuation of the limit switch 252, in response to operation of themandrel switch 100 by the mandrel target 110.

The above described folding operation of the present forming mechanism10, whereby wiping of the adhesively coated outer end flaps F across theend panels E of a carton being formed, is avoided, constitutes oneimportant feature of the invention. Another important feature of theinvention resides in the adjustability of the forming cavity 16 and theforming mandrel 18 to accommodate the forming mechanism 10 to preformedblanks P and end panels E of different sizes. In this regard, it isevident from the earlier detailed description of the forming mechanismthat either or both horizontal dimensions of the forming cavity andforming mandrel may be adjusted to accommodate preformed blanks of arange of dimensions. In this regard, it is significant to recall thatthe width of the inner end flap folding plates 154 is made less than thelength of the inner end flaps F on the smallest blank to be handled,whereby this folding plate width will be compatible with all of theother blank sizes on which the machines is designed to operate. It willbe understood, of course, that the width dimension of the forming cavity.16 in a left-right direction as seen in FIGURE 1 is adjusted byadjusting the hanger assemblies 156 relative to the frame 20. Thecorresponding width dimension of the forming mandrel 18 is adjusted byadjusting the cam follower arms 72 relative to the mandrel thrust plate66. As noted earlier, the mandrel supporting bars 42 are also adjustedto maintainthe mandrel side frames 54 in parallel relationship when thefollower rollers are located in the lower end of their cam slots 82.Adjustment of the width dimension of the forming cavity 16 in the normaldirection, i.e., parallel to the plane of the paper in FIGURE 1 isaccomplished by shifting the rotary side panel folding members 216inwardly toward or outwardly away from the forming cavity, as the casemay be. The corresponding width dimension of the forming mandrel 18 isaccomplished by adjusting the length of the corresponding mandrel sideframe connecting struts 58, 60, and 62. The end panel magazines 139 areadjustable toward and away from the forming mandrel as well as in widthto correspond to the adjusted mandrel dimensions. The mandrel rollerbearing guides 46, obviously, must be correspondingly adjusted alongtheir supporting bars 42. The forming mechanism is adjusted toaccommodate end panels E of various height by adjusting the end paneldrive pawl assemblies 114 up or down relative to the forming mandrel 18,as the case may be.

It is now evident, therefore, that the present carton forming mechanismmay be readily adjusted along all three axes to condition the mechanismfor operating on preformed blanks and end panels of a wide range ofsizes. As a consequence, the present mechanism is capable of producingcartons of a wide range of sizes. H

Another important feature of the invention resides in the fact that theabove described roller and cam slot means 80, 82 for extending andretracting the forming mandrel 18 during its forming and return strokesis relatively noiseless. Accordingly, this mandrel expanding andretracting action does not add appreciably to the overall noise level ofthe machine.

It is now obvious, therefore, that the present forming mechanism isuniquely capable of achieving the advantages herein set forth.

The invention has been described in considerable detail in order tocomply with the patent laws by providing a full public disclosure of atleast one of its forms. However, such detailed description is notintended in any way to limit the broad features or principles of theinvention, or the scope of patent monopoly to be granted.

Having described the invention, what is claimed as new in support ofLetters Patent is:

1. A carton forming mechanism for mating preformed end panels with apreformed blank and erecting said blank about said end panels to form acarton, said blank having a rectangular bottom panel, hinged side panelsalong opposite sides of the bottom panel, and hinged adhesively coatedinner and outer end panel joining flaps along opposite ends of saidbottom and side panels, respectively, said forming mechanism comprising:

a frame,

I means on said frame defining a generally rectangular forming cavityhaving open ends,

a forming mandrel supported on said frame for movement along thelongitudinal axis of said cavity between an extended position, whereinsaid mandrel projects into said cavity through one open end thereof, anda retracted position, wherein said mandrel is retracted from saidcavity,

means for driving said mandrel between said positions,

said mandrel having a generally uniform rectangular cross section inplanes normal to said axis, sides generally parallel to the sides,respectively, of said cavity, and thrust shoulders projecting from twoopposite sides of said mandrel rearwardly of and generally parallel tothe leading end of said mandrel,

said mandrel when retracted being spaced from said cavity to permitplacement of said blank in an initial forming position across said oneend of said cavity wherein said bottom panel overlies said cavity andplacement of said end panels against said mandrel sides forwardly ofsaid thrust shoulders, whereby extension of said mandrel is effective tomove said end panels into initial mating engagement with the bottompanel of said 'blank along the ends of said bottom panel and thereafterto force said blank and end panels into said forming cavity, and

said cavity defining means comprising inner flap folding means operativein response to movement of said blank and end panels into said fo-rmingcavity to initially fold said inner flaps inwardly against the outersurfaces of said end panels, side panel folding means for folding saidside panels of said blank inwardly against the ends of said end panels,and outer flap folding means for initially partially folding said outerflaps inwardly toward said side panels and retaining said outer flaps intheir partially folded positions until said side panels are locatedapproximately in their final folded positions of contact with said endpanels and thereafter finally folding said outer flaps inwardly againstthe outer surfaces of said end panels, thereby to minimize slidingcontact of the confronting surfaces of said end panels and outer flaps.

2. A carton forming mechanism according to claim 1 wherein:

said inner flap folding means comprises fixed folding members at thesides of said cavity adjacent said two mandrel sides, and

said outer flap folding means comprise floating folding members atopposite sides of said fixed folded members, respectively, and means formoving said floating members toward and away from said cavity in timedrelation to movement of said mandrel in suh manner that said floatingmembers are retracted outwardly relative to said fixed members duringthe major portion of each extension stroke of said mandrel to provideclearance for said partially folded outer flaps between said floatingmembers and the end panels of the carton being formed during folding ofthe side panels of the carton blank inwardly to their final foldedpositions of contact with the ends of said end panels, and said floatingmembers are moved inwardly toward said cavity to fold said outer flapsagainst said end panels approximately simultaneously with arrival ofsaid side panels at their final folded positions.

3. A carton forming mechanism according to claim 2 wherein:

said floating members adjacent each fixed member are mutually joined forextension and retraction move ment of the respective floating members inunison.

4. A carton forming mechanism according to claim 1 wherein:

said inner flap folding means comprise fixed inner flap folding platesat the sides of said cavity adjacent and generally parallel to said twomandrel sides, and

said outer flap folding means comprise a pair of floating outer flapfolding plates at opposite sides of and generally parallel to each fixedplate, and means for moving the two floating plate pai-rs toward andaway from said cavity in timed relation to movement of said mandrel insuch manner that said floating plate pairs are retracted outwardlyrelative to said fixed plates during the major portion of each extensionstroke of said mandrel to provide clearance for said partially foldedouter flaps between said floating plates and the end panels of thecarton being formed during folding of the side panels of the cartonblank inwardly to their final folded positions of contact with the endsof said end panels, and said floating plate pairs are moved inwardlytowards said cavity to fold said outer flaps against said end panelsapproximately simultaneously with arrival of said side panels at theirfinal folded positions.

5. A carton forming mechanism according to claim 4 wherein the twofloating plates of each said plate pair are mutually joined forextension and retraction movement of the respective floating plates inunison.

6. A carton forming mechanism according to claim 1 wherein:

said inner flap folding means comprise fixed inner flap folding platesat the sides of said cavity adjacent and generally parallel to said twomandrel sides,

said outer flap folding means comprise floating outer flap foldingplates at opposite sides of said fixed plates, respectively, and meanssupporting said floating plates on said frame for movement toward andaway from said cavity,

said side panel folding means comprise side panel folding members alongthe remaining sides of said cavity and means supporting said panelfolding members on said frame for movement toward and away from saidcavity,

means for moving said side panel folding members toward and away fromsaid cavity in timed relation to movement of said mandrel in such mannerthat said panel folding members are extended inwardly toward said cavityto fold said side panels inwardly to their final folded positions ofcontact with the ends of said end panels in response to predeterminedextension travel of said mandrel, and

means for moving said floating plates in timed relation to the movementof said panel folding mem'bers in such manner that said floating platesare retracted outwardly relative to said fixed plates during the majorportion of each extension stroke of said panel folding members toprovide clearance for said partially folded outer flaps between saidfloating plates and the end panels of the carton being formed duringfolding of the side panels of the carton blank inwardly to their finalfolded positions, and said floating plates are moved inwardly towardsaid cavity to 19 fold said outer flaps against said end panelsapproximately simultaneously with arrival of said side panels at theirfinal folded positions.

7. A carton forming mechanism according to claim 6 wherein:

said means for moving said floating plates comprise actuator means fordriving said floating plates, and means actuated by one of said panelfolding members for operating said actuator means to extend saidfloating plates inwardly toward said cavity in response to arrival ofsaid one panel folding member at its inner extended position.

8. A carton forming mechanism for mating preformed end panels with apreformed blank and erecting said blank about said end panels to form acarton, said blank having a rectangular bottom panel, hinged side panelsalong opposite sides of the bottom panel, and hinged adhesively coatedinner and outer end panel joining flaps along opposite ends of saidbottom and side panels, re spectively, said forming mechanismcomprising:

a frame,

means on said frame defining a generally rectangular forming cavityhaving open ends,

a forming mandrel supported on said frame for movement along thelongitudinal axis of said cavity between an extended position, whereinsaid mandrel projects into said cavity through one open end thereof, anda retracted position, wherein said mandrel is retracted from saidcavity,

means for driving said mandrel between said positions,

said mandrel having a generally uniform rectangular cross-section inplanes normal to said axis, sides generally parallel to the sides,respectively, of said cavity, and thrust shoulders projecting from twoopposite sides of said mandrel rearwardly of and generally parallel tothe leading end of said mandrel,

said mandrel when retracted being spaced from said cavity to permitplacement of said blank in an initial forming position across said oneend of said cavity wherein said bottom panel overlies said cavity andplacement of said end panels against said mandrel sides forwardly ofsaid thrust shoulders, whereby extension of said mandrel is effective tomove said end panels into initial mating engagement with the bottom ofsaid blank along the ends of said bottom panel and thereafter to forcesaid blank and end panels into said forming cavity,

said cavity defining means comprising floating outer flap folding platesat the sides of said cavity adjacent and generally parallel to said twomandrel sides, means supporting said floating plates on said frame forextension toward and retraction away from said cavity, each plate havinga central clearance opening extending endwise of said cavity, fixedinner flap folding plates on said frame generally parallel to andlocated within said clearance openings in said floating plates,respectively, and side panel folding means along the remaining sides ofsaid cavity,

said fixed plates being disposed to fold said inner flaps of the cartonblank being formed inwardly against the outer sides of the carton endpanels in response to movement of said blank and end panels into saidcavity with said mandrel,

said side panel folding means being operative in response to movement ofsaid blank and end panels through said forming cavity with said mandrelto fold said side panels inwardly against the ends of said end panels,

said floating plates when retracted being disposed to fold said outerflaps inwardly to and retain said outer flaps in partially foldedpositions, wherein said outer flaps are disposed to enter between saidfloating plates and said end panels without contacting said end panelsduring inward folding of said 20 side panels to their final foldedpositions of contact with said end panels, and means for moving saidfloating plates toward and away from said cavity in timed relation tomovement of said mandrel in such manner that said floating plates areretracted outwardly relative to said fixed plates during the majorportion of each extension stroke of said mandrel to provide clearancefor said partially folded outer flaps between said floating plates andsaid end panels, and said floating plates are extended inwardly towardsaid cavity to fold said outer flaps against said end panelsapproximately simultaneously with arrival of said side panels at theirfinal folded positions. 9. A carton forming mechanism according to claim8 wherein each said floating plate has a generally U-shape and includestwo generally parallel plate legs defining therebetween said clearanceopening in the respective floating plate,

said side panel folding means comprise side panel folding membersmovably mounted on said frame for extension toward and retraction awayfrom said cavity, and means for moving said panel folding membersinwardly toward said cavity in timed relation to extension of saidmandrel in such manner that said panel folding members fold said sidepanels inwardly to their final folded positions of contact with the endsof said end panels, and

said means for extending and retracting said floating plates compriseactuator means for driving said plates inwardly toward said cavity, andmeans controlled by one of said panel folding members for operating saidactuator means to extend said floating plates inwardly in response toarrival of said one panel folding member at its extended position.

10. A carton forming mechanism according to claim 9 wherein:

said side panel folding members comprise rocker shafts rotatablysupported on said frame and side panel folding arms fixed to saidshafts, respectively, for folding said side panels inwardly to theirfinal folded positions upon rotation of said arms toward said cavity.

11. A carton forming mechanism for mating preformed end panels with apreformed blank and erecting said blank about said end panels on acarton, said blank having a rectangular bottom panel, hinged side panelsalong opposite sides of the bottom panel, and hinged adhesively coatedinner and outer end panel joining flaps along opposite ends of saidbottom and side panels, respectively, said forming mechanism comprising:

a frame, means on said frame defining a generally rectangular formingcavity having open ends, a forming mandrel supported on said frame formove- -ment along the longitudinal axis of said cavity between anextended position, wherein said mandrel projects into said cavitythrough one open end thereof and a retracted position, wherein saidmandrel is retracted from said cavity, means for driving said mandrelbetween said positions, said mandrel having a generally uniformrectangular cross section in planes normal to said axis, sides generallyparallel to the sides, respectively, of said cavity, and thrustshoulders projecting from two opposite sides of said mandrel rearwardlyof and generally parallel to the leading end of said mandrel, saidmandrel when retracted being spaced from said cavity to permit placementof said blank in an initial forming position across said one end of saidcavity wherein said bottom panel overlies said cavity and placement ofsaid end panels against said mandrel sides forwardly of said thrustshoulders, whereby extension of said mandrel is elfective to move said

